The Port of Seattle is moving forward on nearly $1 billion worth of improvements at Seattle-Tacoma International Airport.

The port commission on Tuesday approved a handful of new construction and maintenance proposals that could see construction activity at the airport until the end of the decade, the News Tribune reported (http://is.gd/nWQSHg).

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The projects include creating a new international arrivals complex, reconstructing the airport's center runway, updating the decades-old north and south satellite terminals and building a bridge between the south satellite and international facility.

The costs will be paid for by the airline tenants, the newspaper reported.

The airport located south of Seattle is one of the 15 busiest in the U.S. with about 37 million passengers a year.

The most significant improvements will be focused on two airport satellite terminals north and south of the main terminal.

At the north satellite, the port and Alaska Airlines are reconfiguring and expanding the gates to create a total of 20 gates, up from the current 12. The port commission on Tuesday authorized an additional $191 million for additional gates.

Construction could begin in the fall of 2015. The terminal would continue to operate during renovations.

At the south satellite, where Atlanta-based Delta Airlines is the major occupant, the port plans to spend $5 million to update the terminal's interior.

A large project would build a new facility for international arrivals that would allow passengers to arrive at the south satellite gates as well as gates at the A Concourse. Also, a new overhead bridge would allow international passengers to move from the south satellite to a new arrival facility for customs and immigration clearance, the News Tribune reported.

Preliminary cost estimates say the international facility will cost about $316 million, but port executives expect the final estimate for construction costs will be more than $400 million.